270 EXPERIMENTAL PHARMACOLOGY 



to time to see if any changes are produced in the eyes. If 

 so what explanation can you offer. If no change is pro- 

 duced what explanation can you give ? 



EXPERIMENT LXIIL* 



Atropine. (Dog, Cat or Rabbit: Blood-pressure, Respira- 

 tion, Heart and Vagus Nerve, Dog, Salivary Secre- 

 tion and Chorda Tympani, Sweat Nerves, 

 Pancreatic Secretion.) 



1. Anesthetize a dog, cat (two grains urethane by stom- 

 ach) or rabbit (two grams urethane by stomach) and ar- 

 range for recording blood-pressure and respiration. Iso- 

 late and ligate loosely both vagus nerves. The injecting 

 burettes contain atropine (one cubic centimeter equals one- 

 half milligram) and adrenaline (1:10,000). 



// a dog is used dissect out AVharton's duct and place a 

 cannula in it (Figs. 237, 238, 239, and 240). Also isolate 

 the chorda tympani nerve and stimulate it once or twice to 

 observe the normal rate of salivary secretion. Some opera- 

 tors tie a ligature on the chorda and cut the nerve centrally 

 to the ligature. In this manner the ligature can be used to 

 lift the nerve as desired. Generally it will be sufficient 

 to stimulate the nerve in position without ligating it. (The 

 dissection mav be tried on a cat or rabbit if the instructor 







so advises.) 



Stimulate the vagi and obtain normal records of the ef- 

 fects on the heart, blood-pressure and respiration. Observe 

 the pupils (on the same side) as each vagus nerve is 

 stimulated. 



If time permits, the student may dissect out the sciatic 

 nerve (in dog) and stimulate it to observe the secretion of 

 sweat on the sole of the foot. To do this take a piece of 

 wet cotton and wash the pads of the foot off well, then dry 



*If more than one group performs this experiment, the second group may use scopo- 

 lamine one cubic centimeter equals one milligram instead of atropine. 



